Portable drinking device



FIG. 1 is a top left front perspective view in accordance with our invention thereof;

FIG. 2 is a rear side elevational view thereof, all sides identical thereto;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a reduced scale top left front perspective view thereof, in open condition; and,

FIG. 6 is a reduced scale right side elevational view thereof, in open condition and all sides identical thereto. 

The ornamental design for a portable drinking device, as shown and described. 